//
// Copyright (c) 2004-2024 Jaroslaw Kowalski <jaak@jkowalski.net>, Kim Christensen, Julian Verdurmen
//
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//
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// modification, are permitted provided that the following conditions
// are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
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//   contributors may be used to endorse or promote products derived from this
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namespace NLog.Filters
{
    using NLog.Config;

    /// <summary>
    /// An abstract filter class. Provides a way to eliminate log messages
    /// based on properties other than logger name and log level.
    /// </summary>
    [NLogConfigurationItem]
    public abstract class Filter
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="Filter" /> class.
        /// </summary>
        protected Filter()
        {
            Action = FilterResult.Neutral;
        }

        /// <summary>
        /// Gets or sets the action to be taken when filter matches.
        /// </summary>
        /// <docgen category='Filtering Options' order='10' />
        public FilterResult Action { get; set; }

        /// <summary>
        /// Gets the result of evaluating filter against given log event.
        /// </summary>
        /// <param name="logEvent">The log event.</param>
        /// <returns>Filter result.</returns>
        internal FilterResult GetFilterResult(LogEventInfo logEvent)
        {
            return Check(logEvent);
        }

        /// <summary>
        /// Checks whether log event should be logged or not.
        /// </summary>
        /// <param name="logEvent">Log event.</param>
        /// <returns>
        /// <see cref="FilterResult.Ignore"/> - if the log event should be ignored<br/>
        /// <see cref="FilterResult.Neutral"/> - if the filter doesn't want to decide<br/>
        /// <see cref="FilterResult.Log"/> - if the log event should be logged<br/>
        /// .</returns>
        protected abstract FilterResult Check(LogEventInfo logEvent);
    }
}
